Systems for assembling support structures and the like are well known in the art. Known to the Applicant are the following U.S. patent and patent applications: U.S. Pat. No. 4,090,340; 4,685,258; 4,843,792; 5,259,690; 5,848,501; 5,964,068; 6,006,680; 6,106,186; 6,467,118 B2; 6,581,339 B2; 6,681,981 B2; 6,922,947 B2; 2001/0015045 A1; 2004/0005430 A1; 2004/0020154 A1; 2004/0123529 A1; and 2005/0144857 A1.
It is also well known in the art that, from the moment stage designers wished to use scenic space differently than in a traditional theatre, problems with temporary or semi-permanent load-bearing structures appeared. The properties required to answer their needs evolved in such a manner that they became contradictory: a) “lightness for transportation”, manual handling and visual aspect; b) “sturdiness” for load-bearing capacity, for the capability of integrating other scenic elements and for security concerns; c) optimization of the “minimal number of components” and hardware to facilitate the transfer of the special events from city to city while reducing the set up time; and d) a “better use of space” for equipment storage or the planning of the working space for technicians underneath the structures.
It is also well known that no integrated system existed to completely satisfy these multiple needs emanating from the stage designer's innovative concepts. This is why load-bearing structures destined for entertainment purposes and/or special business events, and the like, to this day, come from the combination of various components designed for other usages.
Indeed, the first modern temporary stages were laid out on flat bed semi-trailers onto which one built a temporary proscenium structure made of plywood and wooden beams on site. The limitations of this installation method were rapidly reached mainly due to the limited performance area of the stage space, the complexity and difficulty to render the installation secure, the impossibility to anchor the complex scenic elements, and the costly and long set up time. Moving the “stage” was done by pinning a tractor to the front of the trailer as with standard trucks. Understandably, this limited this arrangement to exterior events or to theatres and/or amphitheatres able to accommodate a tractor-trailer combination.
Modular scaffolding typically used in the construction business was another option. This system could be used indoors or outdoors, permits a larger performance area and also made adding supplemental technical spaces easier (stage manager's booth, sound and lighting control booths, etc.).
The following description of the main components of this system as used in the scenic domain, namely, a) the section of structure secured with cross-bracing and guy wiring; b) the beam system for the installation of floor and floor panels; and c) the planning of ramps and special configurations; will highlight the inconveniences and limitations of each aspect of such a conventional system.
In regards to the section of structure secured with cross-bracing and guy wiring, the reinforcement of scaffolding sections with cross-braces and guy wires allows a certain point load and dynamic load capacity. However, in a scenic use, the limit of these loads is quickly reached. Indeed, by adding dynamic elements like a stage elevator or a mechanized trap, the scaffolding structure is solicited in upward motion and in torsion, forces for which it is not designed. Therefore, to permit their integration to the scaffold stage base, it is necessary that the scenic elements have their own structure. The task thus becomes complex since standard scaffolding components limit the possible configurations.
From a more practical point of view, the set of legs and cross-braces located under and in the scaffold structure prevents the optimization of the “so-called” utilitarian space under the floor for technical planning, storage or dressing rooms.
In regards to the beam system for the installation of floor and floor panels, to be maintained in place, the beams must be previously attached onto sections of scaffolding. Next, sheets of plywood to make-up the floor must be fixed onto the beams. This process of assembly quickly becomes cumbersome in time and in manpower. To ensure the required structural capacities, the multiplication of beams becomes necessary as, for example, with the “Alumabeam™” type system. This hydride beam results from the combination of an “I” shape aluminium piece that embeds a piece of wood allowing the screwing down of the plywood sheets.
Floor panels are in fact plywood sheets superimposed in two (2) staggered layers. Plywood has a limited point of load bearing, a restricted dynamic load bearing and a weak resilience capacity. To fulfill its role efficiently, the plywood must necessarily be installed with a set of beams to constitute the floor or to permit the integration of a scenic element. In that case, the removal of plywood sheets (for traps, elevators etc.) is often required and inevitably implies the addition of vertical and lateral supports after having made the required analysis of the necessary load distribution.
There exists another type of floor panel among the standard scaffoldings components: the aluminium structure with inset plywood deck. These are laid out side-by-side along the width of the scaffolding sections rendering the screwing down of additional plywood sheets possible.
Among the inconveniences of using plywood sheets in fabricating the floor are the rapid wear of the plywood sheets due to the constant screwing and unscrewing, the need for repeated application of paint on the surface, breakage due to handling and transport, loss of material due to cuts for adjusting finished contours of the installation, the multiplication of costs due to the doubling of plywood sheets as well as the overall handling. Here, the term “handling” is used to designate the work team and the rental of machinery for the loading, installation and dismantling of the scaffolding's structural components.
In regards to the planning of ramps and special configurations, with the system of modular scaffolding, the integration of ramps and levels for lowered or raised floors is complex. Indeed, the structural components used are governed by layouts in pre-established widths and lengths and do not offer the required flexibility.
It is also well known in the art that the principle of a stage using hydraulic deployment, such as Stageline™, is another type of installation. It is made-up of one (1) 45′- or 53′-long trailer of which the two (2) sides fold down using hydraulic actuators to form a floor. The roofs of the trailers are on hydraulic cylinders, and once raised to the correct height, they spread out in width in order to become the roof over the stage. It is an effective system offering several advantages such as its set-up time, the protection that it offers against the weather, and good structural capacities. This stage can be used both outdoors and indoors (in the big amphitheatres). On the other hand, some inconveniences exist, namely: a) confined stage area because enlarging the stage, if required, must necessarily be done by adding scaffolding or another type of temporary structure; b) specialized man-power is required; c) high rental costs; d) impossibility of integrating dynamic stage equipment (turntables, elevators, traps, etc.); and e) this type of stage only offers a unique layout.
It is also known in the art that the Wenger™ stage is another type of temporary structure. Intended for interior use, it consists of platforms with removable telescoping legs. The surface of this platform is made of MDF, encased in a galvanized steel or aluminum frame. The installation is relatively simple: butting together platforms whose legs are extended and using stirrups, positioned under the platforms, to join them together. To facilitate the adjustment of platforms one to the other, some fabricators integrate fastenings elements such as the Rotoloc™ under the MDF sheets. This is a two-part attachment device, operated from above the panel with an hexagonal key, that permits the lateral locking of one part to the other.
The main inconveniences of this type of stage are several, namely: a) the assembly area must be relatively level; b) the joining system between platforms is under the platforms and difficult of access; c) it is impossible to screw directly into the floor surface of this platform; d) to conceal the metal edges of the assembled platforms, double-sided tape is laid along the edges allowing the laying of one or two (2) thicknesses of plywood on top of the platforms—the procedure meets three (3) objectives: to give a regular surface to the assembly, to allow for a screwing surface for the setting up of scenery, and finally, for aesthetic requirements; e) the assembled platforms do not permit an equal spread of loads between them; f) the Rotoloc™ system used between the platforms has no structural value since in does not allow for torsion nor for load-bearing; g) the anchoring and/or integration of dynamic elements, either mechanized or not, is not possible unless one modifies the platform permanently; h) at the time of the application of a dynamic load, a whole series of measures are required to maintain the structural properties of the platforms—these include re-enforcing and stabilising the platform assembly; and i) the assembly of a large area using this platform type with a height lower than about 30 cm becomes difficult since the adjustment of the stirrups takes place under the platforms—additionally, the available heights of the telescopic legs are limited.
It is also known in the art that the folding wooden parallel platform is a rudimentary and temporary structure, traditionally used for opera and theatre for certain limited applications. For installation, the wooden structures are unfolded and then joined together by screwing them one to the other. Next, plywood sheets are laid on the structures and screwed in place. The doubling of plywood sheets is generally required to prevent the deflection of the floor in its center, to increase the structural capacity of the surface and to give a uniform floor surface finish.
This folding wooden parallel platform presents the following inconveniences, namely: a) the friability of the material used to build these platforms limits the life expectancy and the reliability in a frequent set up and tear down context and its resistance to the elements (exterior use); b) the assembly of a large area is labour intensive; c) the plywood floor panels are not bonded to the overall structure but only to the individual platform; d) the anchoring of the scenic elements becomes hazardous; e) costly set-up and adjustment times; f) height is limited; g) the levelling of the structure is complex; and h) the admissible static and dynamic loads are limited. At the most, this type of platform is still used for raising a scenic component or a musical set-up on stage in the case of indoor theatre or a covered outdoor stage.
Hence, in light of the aforementioned, there is a need for an improved system which would be able to overcome some of the aforementioned prior art problems.